6 Octet RuleIn forming compounds, atoms tend to achieve the electrons configuration of a noble gas.An octet does mean a set of 8, but REMEMBER, it does NOT mean an atom wants 8 electrons in its principal energy level- wants to achieve a noble-gas configurationAtoms of metals lose electronsAtoms of nonmetals gain electronsNoble gases (except helium) have 8 electrons in their highest energy levelsThe octet rule takes its name from this fact about noble gases.How many electrons does barium have to give up to achieve a noble-gas configuration?-2How does calcium obey the octet rule when reacting to form compounds?-gives up electrons
7 Ions- CationsCations- positively charged ion produced when an atom loses one or more valence electronsCation = name of the elementCa2+ = calcium ion
8 Ions- AnionsAnions- negatively charged particle produced when an atom gains one or more valence electronsAnion = root + -ideCl- = chlorideWhat is the correct name for the N 3- ion?-nitride ion
9 What is the charge of strontium? -+2What are examples of elements that form an ion with a 1- charge?-Fluorine, chlorine, bromine, iodine
10 Ionic CompoundsAn ionic compound is a compound composed of cations and anions.Ionic compounds are electrically neutral which meansTotal positive charge on cations = total negative charge on anions
11 Ionic BondsThe electrostatic forces that binds oppositely charged ions together.Atoms transfer valence electrons from metal to non-mental or cation to anionWhat occurs in an ionic bond?-oppositely charged ions attractHow many valence electrons are transferred from the calcium atom to iodine?- 2
12 Writing Ionic Compounds Use chemical formula to write the name of compoundsThe formula unit is the lowest whole-number ratio of ions in an ionic compound.Examples : NaCl, CaO, K2OMg2+ Cl MgCl2K Cl KClAl O Al2O3
13 Properties of Ionic Compounds Most ionic compounds are crystalline solids are room temperature.
14 Properties of Ionic Compounds Ionic compounds can conduct an electric current when melted or dissolved in water because their ions are free to move about in the solution.
15 Naming Monatomic IonsA single atom with positive or negative charge resulting from the loss or gain of one or more valence electronsDifferentiate between how to get the charges for metals and nonmetals to form their respective cations and anions.
16 What about the Transition Metals? Form more than one cation with different ionic charges.The charges of the cations of transition metals are determined from the number of electrons lost.
17 How do we name them? Stock system Place a Roman numeral in parentheses after the name of he element to indicate the numerical value of the charge.Fe+2Lead (II) ionIron (II) ionPb+2
18 Binary Ionic Compounds Compound composed of two elements with cation on left and anion on rightIf the metallic element in the compound has more than one common ionic charge, a Roman numeral must be included in the cation name.Iron (III) OxidePbOSodium SulfideNa3N
19 Practice What is the formula unit: Magnesium Chloride Potassium ChlorideAluminum Oxide
20 Practice Sodium Sulfide Na3N Copper (II) Sulfide CoI2 Aluminum Oxide Li2Se